Misplaced keyboard icons

I recently bought graphics tablet and have yet to v=become proficient with it, in one of my attempts to use it to navigate my desktop after practicing drawings I somehow forced all windows/icons to move further right off the left edge off the screen. When I moved them back into their previous place, they dissapeared.
How would I go about getting them back?I am running Windows 7 Ultimate.Thanks in advance.

Rebooting works. OR Right Click> and make sure of all of the options are selected.